> But if the answer is "no", I cannot see how that justifies you getting a copy without paying. Where else in life is that a valid option? "I'd love to have a snickers bar, but I don't want to pay a dollar for it, so I guess I just take it." Obviously, there are differences between that example and sci-hub but for the core of the issue, these differences are negligible in my opinion.
I think the differences are definitely not negligible. There are similarities on the surface, yes, but one can distinguish between the two cases by asking "would it be OK if everyone did this?"
Basically Kant's categorical imperative:
> Act only according to that maxim whereby you can, at the same time, will that it should become a universal law
In the case of stealing snickers, we can imagine that if everyone did so, then making or selling snickers would no longer be a profitable business, so in the end snickers would no longer be produced, and we would all be worse for it :(
On the other hand, if everyone were to pirate scientific papers, no economic harm would come to the scientists doing the research for those papers. Only the journals would risk going out of business if they don't adapt, and that would be (or could be; i'm not entirely sure) a good outcome, as it would incentivize a more open approach to science distribution and access :)
So, one can conclude that, despite the surface similarities, stealing snickers is morally wrong, while pirating scientific papers is not.